One vertex per element, one color per generator, with an edge from x to x·s.
(2,5)(6,8)(9,10,13,16)(11,14,17,21)(12,19,20,15)(18,24,23,22)(25,26,31,36)(27,32,28,38)(29,35,30,34)(33,39,40,37)(1,2)(3,6)(4,5)(7,8)(11,17)(12,20)(14,21)(15,19)(25,27,31,28)(26,32,36,38)(29,39,30,37)(33,35,40,34)(1,3,4,7)(2,6,5,8)(9,11)(10,14)(12,18)(13,17)(15,22)(16,21)(19,24)(20,23)(25,27)(26,33)(28,31)(29,37)(30,39)(32,34)(35,38)(36,40)(2,5)(6,8)(11,17)(14,21)(18,23)(22,24)(25,28,31,27)(26,32,36,38)(29,37,30,39)(33,35,40,34)(9,12,13,20)(10,15,16,19)(11,18,17,23)(14,22,21,24)(25,29,31,30)(26,34,36,35)(27,37,28,39)(32,40,38,33)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.